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Matthew S. Wandishin, David J. Stensrud, Steven L. Mullen, and Louis J. Wicker

boundary layer. The wind profile for the control run increases linearly from 0.0 to 17.5 m s −1 at 2.5 km above the surface and no shear above that height; this is the same wind profile as used by Rotunno et al. (1988) . Microphysical processes are modeled by the three-class ice parameterization of Gilmore et al. (2004) , which is a variant of the Lin et al. (1983) scheme. Perturbation sizes for this experiment are based on forecast errors from the 12-km North American Model (NAM, formerly the Eta

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David R. Novak, Christopher Bailey, Keith F. Brill, Patrick Burke, Wallace A. Hogsett, Robert Rausch, and Michael Schichtel

NCEP North American Mesoscale (NAM) model ( Janjić 2003 ), Global Forecast System (GFS; Caplan et al. 1997 ), and European Centre for Medium-Range Weather Forecasts (ECMWF; Magnusson and Kallen 2013 ), and a full ensemble part composed of the high-resolution ensemble plus the Canadian Global Environmental Multiscale Model (GEM; Bélair et al. 2009 ), Met Office model (UKMO), and all members of the NCEP Short-Range Ensemble Forecast (SREF; Du et al. 2006 ). The product is objectively downscaled

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Huiling Yuan, Chungu Lu, John A. McGinley, Paul J. Schultz, Brian D. Jamison, Linda Wharton, and Christopher J. Anderson

. Convective cumulus schemes were not used in either of the models with horizontal grid spacing of 12 km. Both models were initialized every hour by the LAPS diabatic initialization and run over a west-central United States domain ( Fig. 3 ) with 128 × 128 horizontal grid points and 31 vertical levels. The lateral boundary conditions were provided by the NCEP North American Mesoscale (NAM, the former Eta Model; information online at http://www.meted.ucar.edu/nwp/pcu2/NAMMay2005.htm ) model at 40-km

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William Y. Y. Cheng and W. James Steenburgh

, such as KF and running-mean bias removal, perform relative to MOS and under what conditions these alternative postprocessing methods produce better forecasts. Specifically, we evaluate three postprocessing methods for improving 2-m temperature, 2-m dewpoint, and 10-m wind speed and direction forecasts produced by the Eta/North American Meso (NAM) 1 model: (i) traditional MOS (ETAMOS), (ii) the Kalman filter (ETAKF), and (iii) a 7-day running mean bias removal (ETA7DBR). We focus on surface

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Michael C. Coniglio, Kimberly L. Elmore, John S. Kain, Steven J. Weiss, Ming Xue, and Morris L. Weisman

al. (2009) all found that 4-km WRF forecasts with explicitly resolved convection yielded better guidance for precipitation forecasts than did the 12-km North American Mesoscale (NAM) model that uses convective parameterization. Additionally, these experiments revealed that running the WRF model at 4 km without convective parameterization does not result in grossly unrealistic precipitation forecasts, even though a 4-km grid is too coarse to fully capture convective scale circulations ( Bryan et

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Cristina Forbes, Richard A. Luettich Jr., Craig A. Mattocks, and Joannes J. Westerink

compare hindcast water levels forced by 1) the AWM using NHC best-track data, 2) National Oceanic and Atmospheric Administration (NOAA) HRD H*Wind analyses, and 3) gridded North American Mesoscale (NAM) model wind fields to evaluate the storm surge model skill. The storm surge and wind model are described in section 2 . Forecast simulations, tracks, and storm surge predictions are described in sections 3 and 4 . Hindcast water levels and wind results are reported in section 5 . Comparisons of

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Matthew T. Bray, Steven M. Cavallo, and Howard B. Bluestein

majority of these anomalies could be traced back to the Arctic, thereby qualifying as TPVs, while the remainder formed over the North Pacific. The individual vortices associated with each outbreak followed a similar path into the United States, traveling across the North Pacific before dropping southward along the west coast of North America. These vortices were found to be significantly more anomalous and slightly longer-lived than average, suggesting that these outbreak-related TPVs may share some

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Andrew W. Ellis and Daniel J. Leathers

across the Northern Hemisphere. J. Climate, 5, 1441–1447. 10.1175/1520-0442(1992)005<1441:IVOWSC>2.0.CO;2 Heim, R., Jr., and K. F. Dewey, 1984: Circulation patterns and temperature fields associated with extensive snow cover on the North American continent. Phys. Geogr., 4, 66–85. 10.1080/02723646.1984.10642244 Idso, S. B., 1981: A set of equations for full spectrum and 8–14 μ m and 10.5–12.5 μ m thermal radiation from cloudless skies. Water Resour. Res., 17, 295–304. 10.1029/WR

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Bruce B. Smith and Steven L. Mullen

(Manuscript received 4 May 1992, in final form 13 October 1992) ABSTRACT Sea level cyclone errors are computed for the National Meteorological Center's Nested-Grid Model (NGM)and the Aviation Run of the Global Spectral Model (AVN). The study is performed for the 1987/88 and 1989/90 cool seasons. All available 24- and 48-h forecast cycles are analyzed for North America and adjacent oceanregions. Forecast errors in the central pressure, position, and 1000-500-mb thickness of the cyclone center

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Jonathan L. Case, Sujay V. Kumar, Jayanthi Srikishen, and Gary J. Jedlovec

. Koster et al. (2004) ran retrospective atmospheric general circulation model simulations initialized with realistic land surface model (LSM) fields to show the importance of a proper land surface initialization on the forecast skill of summer precipitation over the North American Great Plains. Soil moisture heterogeneity can lead to the development of mesoscale circulations that are nearly as strong as sea-breeze circulations ( Ookouchi et al. 1984 ; Avissar and Pielke 1989 ). These mesoscale

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